Scrubby slider

Adobe shipped these as scrubby sliders and the name stuck: put the pointer on the little word or icon beside a numeric field, drag sideways, and the number runs with you. Every professional tool has some version now. Photoshop scrubs almost every field it has, After Effects scrubs its property values, and Figma scrubs the labels in its inspector, which is why a designer moving between them expects the gesture on any number they meet. What it buys is real estate. A slider needs a track wide enough to be worth aiming at, and an inspector panel with twenty numbers in it has room for none of them, so the label becomes the track and the whole control costs nothing.

The value has to track the pointer continuously rather than in visible jumps, because the feel is the entire point: this is coarse adjustment by hand, the same thing a slider is for. Two refinements make it usable. Sensitivity should be a ratio rather than one unit per pixel, so a value that runs to ten thousand is still reachable and a value from zero to one is still controllable, and modifier keys should offer a second and third ratio, which is the convention Adobe set (a modifier for finer, another for coarser). The other refinement is what happens at the edges of the screen. A long scrub runs out of monitor, so the serious implementations request pointer lock, hide the cursor, and accumulate raw movement instead, which turns the gesture into something with no boundary at all. Pointer capture is the cheaper half of that and the part you always need: without it the drag stops the moment the pointer leaves the label.

None of this is discoverable, so the field has to say it. The reliable signal is the cursor, which changes to the horizontal resize arrows when the pointer is over the label, and the reliable rule is that the field still behaves like a field: a click puts a caret in it and lets a person type an exact number, because scrubbing is for approximating and typing is for knowing. Keep the two gestures on separate parts of the control, label for dragging and box for typing, or a stray click during a scrub will select text you did not mean to select.

The word sits between two neighbours on this site. A slider is the version with a dedicated track, where the position of a thumb is the value and the control is legible without being touched. Scrubbing means dragging along a media timeline, where the thing being changed is playback position rather than a number in a field. And because a scrubby slider is a drag with no keyboard equivalent of its own, the field it lives in owes one anyway: arrow keys that nudge by the same step, so the value is reachable without the gesture at all.